Is Higher Antenna Gain Better?
In modern communication technology, antenna plays a crucial role as a transmitting and receiving device for radio signals. The performance of antenna directly affects the quality and efficiency of wireless communication, and one of the key performance indicators is the antenna gain. In this paper, we will discuss in depth what is antenna gain, and whether the higher the gain, the better.
Antenna Gain
1.What is the gain of antenna ?
Antenna gain is an important factor in an antenna’s ability to send and receive signals. Simply put, gain tells us how well an antenna focuses a signal in one direction compared to a perfect antenna that spreads the signal evenly in all directions.
A perfect antenna would act like a ball, spreading the signal evenly in all directions. But real antennas are not like that. They will focus the signal more strongly in certain directions, which means you’ll get better coverage in those directions, but less coverage overall. This balance is important when choosing the right antenna for your IoT network!
The antenna gain is closely related to the antenna radiation pattern, the narrower the main lobe, the smallerside lobe, the higher the gain. The relationship between the main lobe width and antenna gain is shown in below picture.
2.Related Concepts:
- dBd: unit for measuring the balanced dipole’s gain.
- dBi: unit for measuring the radiation source antenna’s gain, with equal signal radiation in all directions. dBi = dBd + 2.15.
- Lobe angle: defined as the angle between the points in the main lobe that are down from the maximum gain by 3 dB.
- Ideal radiation source: ideal isotropic antenna, that is, a simple point-shaped radiation source that provides the same radiation performance in all directions
3.Formula:
Antenna gain = 10lg(Power density of an antenna/Power density of a reference antenna)
The higher the antenna gain, the better?
After understanding the principle of radiation of antenna gain, let’s go back to the beginning of the question, antenna gain is not the higher the better? Obviously not.
The higher the antenna gain, the greater the coverage distance, but at the same time will narrow the beam (radiation area) width, resulting in coverage uniformity deterioration. Antenna gain should be selected on the premise of matching the beam and target area, in order to improve the gain and overly narrow the vertical beam width is not desirable.
As shown in the figure below: the higher the gain, the narrower the beam width in the vertical direction; and vice versa.
The best method is to improve the antenna gain by optimizing the scheme to achieve a rapid drop in the level outside the service area, suppressing the side lobes and back lobes, reducing the cross-polarization level, and using a feed network with low-loss, no surface wave parasitic radiation and low VSWR , etc. This is the right way to improve the antenna gain.
Although the higher the antenna gain, the better the signal and the longer the transmission distance, the higher the gain, the smaller the vertical coverage, so when choosing an antenna, you also need to take into account the actual application environment, and if it is a high-volume use, you can also consider the antenna customized design, customize the best antenna solution in order to achieve the best transmission distance of the equipment.
